class Animal:
     def speak(self):
         print("动物的叫声")

class Cat(Animal):
     def speak(self):
         print("喵喵")

class Dog(Animal):
     def speak(self):
         print("汪汪")

class Test(object):
     def speak(self):
         print("test")

def speak(object): # Animal
    object.speak()

animal = Animal()
animal.speak()

kitty =  Cat()
kitty.speak()
puppy = Dog()
puppy.speak()

print("🍎" * 20)

speak(animal)
test = Test()
speak(test)


